Aggregation of chemotactic organisms in a differential flow

TL;DR

This paper investigates how differential flow influences chemotactic aggregation, revealing that flow can induce anisotropic patterns, alter dynamics, and suppress coarsening in chemotactic systems modeled by Keller-Segel equations.

Contribution

It demonstrates analytically and numerically that differential flow significantly modifies aggregation patterns and dynamics in chemotactic models, a novel insight into flow-chemotaxis interactions.

Findings

Flow causes anisotropic aggregate formation.

Strong advection halts coarsening along flow direction.

Flow can induce movement of aggregates following the flow.

Abstract

We study the effect of advection on the aggregation and pattern formation in chemotactic systems described by Keller-Segel type models. The evolution of small perturbations is studied analytically in the linear regime complemented by numerical simulations. We show that a uniform differential flow can significantly alter the spatial structure and dynamics of the chemotactic system. The flow leads to the formation of anisotropic aggregates that move following the direction of the flow, even when the chemotactic organisms are not directly advected by the flow. Sufficiently strong advection can stop the aggregation and coarsening process that is then restricted to the direction perpendicular to the flow.